1. Field of the Invention
The present invention relates to an electrochemical device such as a secondary battery, an electric double layer capacitor, or the like, and a method of manufacturing the device.
2. Description of the Related Art
So-called electrochemical devices capable of storing an electric charge, such as secondary batteries such as lithium-ion batteries and nickel halide batteries, and electrochemical capacitors such as electric double layer capacitors and redox capacitors, are widely used in, for example, electric apparatuses such as cellular phones, digital still cameras, notebook-sized personal computers, and hybrid electric automobiles.
As this type of conventional electrochemical device, for example, Japanese Unexamined Patent Application Publication No. 2006-278897 discloses an electrochemical device including a pair of current collector plates each having a main part and a tab part and disposed so that the main parts are opposed to each other, a separator having a main part and a tab part and disposed so that the main part is disposed between the main parts of the pair of current collector plates and the tab part projects from between the main parts of the pair of collector plates, an active material layer formed on each of the main parts of the pair of current collector plates so as to contact the separator, an electrolyte in contact with each of the active material layers, and an insulating fixing member for fixing the tab part of each of the collector plates and the tab part of the separator.
Japanese Patent No. 3531552 discloses an electrode structure for a multilayer battery/capacitor, in which pluralities of positive electrode plates and negative electrode plates are alternately laminated, and electrically insulating separators are interposed between the adjacent positive and negative electrode plates. Each of the separators has a positioning portion in a portion other than the contact part with the positive or negative electrode plate and including a projection formed by partially deforming the portion in the thickness direction thereof. The projection of each separator is engaged in a recess formed on the back of the projection of the adjacent separator so that the positioning portion positions the positive or negative electrode plate on each of the separators and positions the adjacent separators.
Further, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2004-515083 discloses a method of manufacturing a super capacitor including forming a polarizable electrode on a continuous sheet-shaped current collector and laminating a separator on the polarizable electrode which has been divided by slits.
However, the electrochemical device disclosed in Japanese Unexamined Patent Application Publication No. 2006-278897 requires the insulating fixing member for fixing the tab part of each of the collector plates and the tab part of the separator, thereby increasing the number of components and thus causing the problem of complicating the manufacturing process.
In addition, the electrochemical device disclosed in Japanese Patent No. 3531552 requires forming the projection on each separator and engaging together the projections of the adjacent separators, thereby complicating the manufacturing process.
Further, the method of manufacturing a super capacitor disclosed in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2004-515083 includes forming slits for dividing the polarizable electrode from one of the sides of the sheet, thereby failing to support both sides of the sheet in lamination by a roll-to-roll process and thus causing the problem of failing to stably support the sheet.